Risk factors associated with long-term prognosis of patients with Staphylococcus aureus bacteremia

To estimate risk factors associated with long-term outcome (i.e., 1-year survival) in patients with Staphylococcus aureus bacteremia (SAB).

This was a retrospective study in which the microbiological laboratory data records of patients admitted to the University Hospital of Regensburg between January 2004 and June 2005 were examined to identify those patients with blood cultures positive for S. aureus. Corresponding clinical records for all patients were reviewed using a standardized questionnaire. Of the 119 patients identified with SAB, 80 were available for the >1-year follow-up.

Crude 1-year mortality was 47.5; 30- and 90-day mortality was 28.8 and 37.5%, respectively. In-hospital mortality was 28.8%. There were no significant differences in 1-year survival in terms of age, gender, antibiotic resistance, and mode of acquisition (nosocomial vs. community-acquired). A significantly better survival was observed with an identifiable focus present, if the chosen empiric antibiotic therapy was adequate or if the body mass index of the patient was >24.

In summary, in this patient cohort, considerable additional mortality due to SAB beyond 30 or 90 days was present. Our results suggest that long-term survival data should be taken into account in outcome studies involving patients with S. aureus bacteremia.